LayoutFarm.HtmlBoxes.SelectionRange.FindCommonGround C# (CSharp) Method

        static bool FindCommonGround(CssBoxHitChain startChain, CssBoxHitChain endChain, out int breakAtLevel)
        {
            //find common ground of startChain and endChain
            int startChainCount = startChain.Count;
            int endChainCount = endChain.Count;
            int lim = Math.Min(startChainCount, endChainCount);
            //from root to leave
            breakAtLevel = 0;
            for (int i = 0; i < lim; ++i)
            {
                var startHitInfo = startChain.GetHitInfo(i);
                var endHitInfo = endChain.GetHitInfo(i);
                if (startHitInfo.hitObject != endHitInfo.hitObject)
                {
                    //found diff here
                    breakAtLevel = i;
                    break;
                }
            }
            //----------------------------
            //check  
            //return isDeepDown = endChainCount > startChainCount && (breakAtLevel == startChainCount - 1);
            return endChainCount > startChainCount && (breakAtLevel == startChainCount - 1);
        }